For example, in the field of manufacture of a semiconductor device, an etching process, a film forming process or the like is performed by allowing plasma to act on a target substrate to be processed, such as a semiconductor wafer, by means of a plasma processing apparatus when forming a fine circuit structure of the semiconductor device.
In such plasma processing apparatus, since the plasma process is performed while accommodating the target substrate in a plasma processing chamber within a vacuum chamber maintained under depressurized atmosphere, it is difficult to attract and hold the target substrate by a vacuum chuck. Thus, an electrostatic chuck is utilized as a device for attracting and holding the target substrate. The electrostatic chuck is configured by disposing an electrostatic chuck electrode made of tungsten or the like between insulating members such as ceramics. Further, the target substrate is attracted and held by the Coulomb force generated by applying a DC voltage to the electrostatic chuck electrode.
Further, in the plasma processing apparatus, a substrate mounting table for mounting thereon the target substrate also serves as a lower electrode, and a base of the substrate mounting table needs to be made of a conductive metal such as aluminum. In this regard, as disclosed in, for example, Japanese Patent Laid-open Publication No. 2004-47653 (Patent Document 1), there is known a substrate mounting table configured by attaching an insulating member of an electrostatic chuck to a base made of aluminum or the like by using an adhesive. In this structure, the electrostatic chuck is a separate component from the base, and the insulating member is made of ceramics or the like.
The substrate mounting table is configured by fastening the electrostatic chuck made of the ceramics or the like onto the base formed of the aluminum or the like. The surface of the base is coated with an insulating film so as to prevent the base from being exposed to a highly corrosive processing gas, and the electrostatic chuck is fixed on the insulating film. To prevent an end portion of the insulating film from being exposed to the processing gas, a cavity such as a groove is provided in Patent Document 1, and the end portion of the insulating film is brought into contact with the cavity, and a helium gas is supplied into the cavity.    Patent Document 1: Japanese Patent Laid-open Publication No. 2004-47653